BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to methods for providing connector assemblies on tube ends, and, more particularly, to a process for forming radially upset flanges to secure a connector on the end of a tube, and to a connector assembly formed by the process.
2. Description of the Related Art
It is known in fluid transportation systems utilizing tubes of steel, copper or other metals to form a connector assembly on the end of the tube, for connecting the tube to another component of the fluid system, or to a complementary connector assembly on another tube section. A connector assembly includes a tube and a connector provided on the tube at an end portion of the tube. The connector may take the form of a nut, a female connector of another design, or a male connector of suitable form and function. It is also known, when coupling together connector assemblies of adjacent fluid system components, to provide a sealing member associated with the connectors, to create a fluid tight seal. It may be required that the connector be permitted to rotate on the tube end, to establish the connection between the connectors, but the connection must be tight i.e., not permitting fluid to leak from the connector assembly. For a proper, fluid tight engagement between the connectors, any sealing member used must be properly positioned.
It is desirable to have the sealing member maintained in proper position by the structure of the connector assembly itself, to minimize the possibility that the sealing member would become mispositioned. It is also desirable that the connector assembly is axially secured near the end of the tube, that is the connector is restricted from moving significantly in either direction axially on the tube.
It also is known to provide a flared end on a tube, to provide a sealing surface against which the tube can be mated to another tube or system component. The flared end may also be used to prevent the connector from passing off the end of the tube. However, it is preferred that axial movement of the connector be inhibited by other than the flared end, as distortion of the flared end may result in fluid leakage at the connection. For this reason, radially outward upsets of the tube have been used to secure the position of the connector on the tube. Creating the radially outward upsets has been neither easy nor simple, often requiring multiple steps, increasing manufacturing expense.
What is needed is a simplified manufacturing process for securing a connector at the end of a tube. What is further needed is a tube and connector assembly which can be manufactured in a simple and efficient manner, and which incorporates the desirable features for such an assembly, including restraining the connector against axial movement on the tube and providing a sealing flange and a properly positioned sealing member for creating a fluid tight seal.
SUMMARY OF THE INVENTION
The present invention provides a process for forming radially outward upsets, or deformations, in tubes, in a simplified sequence of steps, and further provides a tube connector assembly formed by the process. Radially outward upsets can be formed substantially simultaneously at opposite ends of a connector positioned on the tube, and a sealing member can be secured in place on the tube while forming a flared end on the tube.
The invention comprises, in one form thereof, a method of securing a connector on an end of a tube. A connector is provided, having an end face and an away face. A desired length of tube is provided, having an end portion and a tube end. The connector is passed over the end portion of the tube, with the end face of the connector nearest the tube end and the away face of the connector farthest from the tube end. The tube is gripped with a fixture, and positioned with the away face of the connector against the fixture. A preferred length of the tube end portion extends axially beyond the end face of the connector. The end of the tube is impacted axially, causing a major radially outward upset of the tube against the end face of the connector and a minor radially outward upset of the tube against the away face of the connector. A tapered punch is forced into the tube axially, at the tube end, causing the end of the tube to flare outwardly. The tube is released from the fixture.
The invention comprises, in another form thereof, a tube end connector assembly. A length of tube has a tube end portion, a tube end and a tube axis. A connector is disposed on the tube end portion, the connector having an end face nearest the tube end and an away face. A major radially outward upset of the tube is disposed against the connector end face, and a minor radially outward upset of the tube is disposed against the connector away face.
The invention comprises, in yet another form thereof, a process for forming a flanged tube. A section of tube is provided, having a tube end. The tube is secured against axial movement by grasping the tube in a fixture. External support of the tube is provided along regions of the tube between the tube end and the fixture where a radially outward flange is not desired. Regions without external support are provided between the tube end and the fixture where a radially outward flange is desired. An axial force is applied to the tube end, causing portions of the tube to buckle outwardly at the regions without external support.
An advantage of the present invention is that a simplified manufacturing process is provided for securing a connector on a tube.
Another advantage of the present invention is in providing a tube end connector assembly which can be manufactured efficiently, having a connector secured near the end of the tube, with the connector restrained from axial movement along the tube.
Yet another advantage of the present invention is that a simplified manufacturing process is provided for forming flanged tubes with flanges in a plurality of discrete locations along the tube length.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of (an) embodiment(s) of the invention taken in conjunction with the accompanying drawing(s), wherein:
FIG. 1 is a cross-sectional view of a tube connector assembly of the present invention;
FIG. 2 is a cross-sectional view similar to that of FIG. 1, but showing an early stage in the process for manufacturing the tube connector assembly shown in FIG. 1;
FIG. 3 is a cross-sectional view similar to that of FIG. 2, but showing a later stage in the process for manufacturing the tube connector assembly shown in FIG. 1; and
FIG. 4 is a cross-sectional view similar to that of FIG. 3, but showing a final stage in the process for manufacturing the tube connector assembly shown in FIG. 1.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIG. 1, there is shown a tube
end connector assembly 10 according to the present invention and manufactured in accordance with the process of the present invention.
Tube
end connector assembly 10 includes a
tube 12 and a
connector 14 secured on
tube 12 at an
end portion 16 of
tube 12.
Tube 12 and
connector 14 may be of metal such as steel, copper or the like, the material for
tube 12 and
connector 14 being selected based on the properties necessary for the fluid transportation system in which they will be utilized. The size, shape and structure for
tube 12 and
connector 14 are also selected based on the requirements of the fluid transportation system in which they will be used.
End portion 16 of
tube 12 includes a
tube end 18.
Tube 12 may include a
connector 14 at each end thereof; however, only one such
tube end portion 16 and
connector 14 are shown in FIG.
1.
Connector 14 is shown as a male
connector having threads 20 for engagement with complimentary threads of a female connecting member (not shown) which may be provided on another section of tube to which
tube 12 is to be connected, or on another component in the fluid transportation system in which
tube 12 is used.
Connector 14, as shown in the drawings, is merely one suitable type of connector which may be part of tube
end connector assembly 10, and it should be readily understood that female connectors may be part of a tube
end connector assembly 10 in accordance with the present invention, as may be other types of connectors including spring loaded snap type connectors as well as screw connectors of other types. As used herein, the term connector shall mean any suitable male or female component, or any other device that may be fastened to a tube, and is useful for securing a tube to another tube or to a system component in a fluid transportation system.
Connector 14 includes a
central bore 22 of slightly greater diameter than the outer diameter of
tube 12, thus allowing
connector 14 to slide over
end portion 16 of
tube 12. It will be understood by those skilled in the art that it may be necessary, depending on the type of
connector 14 being used, for
connector 14 to rotate about an
axis 24 of
tube 12. Rotation of
connector 14 may be generated through a
head 26, which may be shaped for engagement by a wrench or the like.
Head 26 may also include a knurled outer body surface (not shown), when
connector 14 is to be rotated by hand.
Connector 14 includes a
connector end face 28 and a connector away
face 30, each the
end face 28 and away face
30 being generally orthogonal to
tube axis 24. As positioned on
tube 12, connector end face
28 is that end of
connector 14 nearest tube end 18, and away face
30 is that end of
connector 14 furthest from
tube end 18.
At the juncture between
connector end face 28 and connector central bore
22, a
major recess 32 defines a pocket formed as a cutback from each
end face 28 and
central bore 22. While shown as a general parallel cutbacks from each
end face 28 and
central bore 22, it should be recognized that
major recess 32 need not be a right angle pocket as shown in FIG. 1 but may include other shapes as well.
Major recess 32 is a recessed segment of end face
28 as well as a recessed segment of
central bore 22, and references herein to end
face 28 and
central bore 22 shall be understood to include
major recess 32.
At the opposite end of
connector 14 from
major recess 32, a
minor recess 34 is formed in the juncture between away face
30 and
central bore 22.
Minor recess 34 is a cutback from each away
face 30 and
central bore 22, and as shown in FIG. 1,
minor recess 34 is a tapered segment of away face
30 at the juncture between away face
30 and
central bore 22. Again, it will recognized by those skilled in the art that the shape of
minor recess 34 may be other than as shown in the drawings.
Minor recess 34 is a recessed segment of each away
face 30 and
central bore 22, and references herein to away
face 30 and
central bore 22 shall be understood to include
minor recess 34.
End portion 16 of
tube 12 includes a minor radially outward upset
36 which is disposed substantially in
minor recess 34 of
connector 14. Minor radially outward upset
36 is a bump, ridge or minor outward protrusion of
tube 12.
Tube 12 further includes a major radially outward upset
38 disposed in
major recess 32 of
connector 14. Major radially outward upset
38 is a more pronounced outward upset than is minor radially outward upset
36, and in the embodiment shown in FIG. 1, major radially outward upset
38 is a folded
segment 40 of
tube 12.
It should be understood that major radially outward upset
38 and minor radially outward upset
36, while shown to be significantly different in size, may also be of similar size and shape. However, the function of minor radially outward upset
36 is primarily to restrain
connector 14 from sliding on
tube 12, away from
tube end 18. Therefore, a small protrusion in
tube 12 is sufficient, as minimalforce will be exerted on minor radially outward upset
36 in normal use. On the other hand, major radially outward upset
38 becomes a bearing surface against which
connector 14 exerts force when a connection is made to a complimentary fitting of another tube or component of the fluid transportation system.
Major recess 32 advantageously includes a
floor 42 and a
side wall 44 defining the recess. Folded
segment 40 of
tube 12 has a double layer of tube wall, including a
lower segment 46 and an
upper segment 48 which rest on
floor 42 of
major recess 32. Significant loading force can be applied by
floor 42 to folded
segment 40, in drawing
tube end 18 toward and against a component to which it is connected, to create a fluid tight connection.
At a minimal axial length from
tube end 18, a flared
portion 50 is provided. A sealing member, such as an o-
ring 52, is provided also generally disposed in
major recess 32. O-
ring 52 is wedged between
wall 44 of
major recess 32 and tube end
18 at outwardly flared
portion 50. O-
ring 52 is thereby retained in position by
wall 44 and flared
portion 50, and o-
ring 52 generally rests on folded
segment 40 and particularly on
upper segment 48 of folded
segment 40. O-
ring 52 projects slightly beyond
tube end 18 and
connector end face 28, in an axial direction relative to
tube 12.
FIGS. 2,
3 and
4 illustrate steps in a process for forming tube
end connector assembly 10. Referring first to FIG. 2, an early stage in the manufacturing process is illustrated.
Tube 12 is a cylindrical body with an essentially smooth outer surface having no significant dimples or outward projections or flanges along
end portion 16. A desired length of
tube 12 is clamped in a
fixture 60, which may be a multi-piece
device encircling tube 12 and clamping the tube therein, restricting axial movement of the tube.
Connector 14 is slid over
end portion 16 of
tube 12, and away face
30 of
connector 14 rests against an
upper face 62 of
fixture 60.
Upper face 62 includes a tapered
surface 64 extending downwardly and inwardly from
upper face 62 of
fixture 60. The inner edge of tapered
surface 64 extends to the outer surface of
tube 12, and tapered
surface 64 together with
minor recess 32 defines a
cavity 66.
A
punch 68 includes a
probe portion 70 which can slide into
tube 12. A
shoulder 72 extends radially outwardly from
probe portion 70 and extends beyond the outer surface of
tube 12. Through
shoulder 72, punch
68 applies force axially to tube end
18, compressing
tube end portion 16 between
tube end 18 and
fixture 60. While an abrupt force may be applied to tube end
18, such as by an impact, force also may be applied as a progressive compressive force. As shown in FIG. 3, as axial force is applied to tube end
18, the tube bends radially outwardly, in regions between
fixture 60 and tube end
18 whereat no external support of the tube is provided.
Connector 14 provides external support of the tube between
major recess 32 and
minor recess 34, preventing outward deformation therealong. Inward deformation of
tube 12 is inhibited by the hoop strength of
tube 12, and may be further inhibited through internal support provided by
probe portion 70, which may extend within
tube 12 beyond
fixture 60.
In a single operation, minor radially outward upset
36 is formed in
cavity 66 and major radially outward upset
38 is formed in
major recess 32.
Shoulder 72 may include a portion providing external support of the tube for a minimal distance inwardly from
tube end 18. Support in such manner could be created by providing in shoulder
72 a groove (not shown) having a depth substantially equal to the length of tube to remain between folded
segment 40 and
tube end 18.
Punch 68 thereby can provide both internal support and external support for a region of
tube end portion 16. The portion of
shoulder 72 radially outward from such a groove could be used for tamping down or compressing folded
segment 40 if required; however, in many applications it is not believed that such will be necessary.
As shown in FIG. 2, a
preferred length 74 of
tube end portion 16 extends beyond
connector 14 when
tube 12 is secured in
fixture 60, and
connector 14 is positioned thereon. The dimension of
preferred length 74 is such as to provide sufficient tube material to form folded
segment 40 and flared
portion 50.
When axial impacting of
tube end 18 is complete, and minor radially outward upset
36 and major radially outward upset
38 have been formed, punch
68 is withdrawn from
tube 12. A sealing member such as o-
ring 52 is placed around
tube 14, in
major recess 32, essentially resting upon folded
segment 40, and particularly
upper segment 48 thereof, between an end
most portion 78 of
tube 14 and
wall 44 of
major recess 32. A
tapered punch 80 is inserted into
tube end 18, and has a
probe portion 82 similar to but perhaps shorter than
probe portion 70 of
punch 68. A tapered
face 84 extends outwardly from
probe portion 82, and, as tapered
punch 80 is forced into
tube end 18, tapered
face 84 urges end
most portion 78 outwardly, thereby forming flared
portion 50 of the completed assembly. Outward flaring of end
most portion 78 creates a minimal clearance separation between
tube end 18 and
wall 44, trapping o-
ring 52 in the position described.
Upon completion of forming flared
portion 50, tapered
punch 80 is removed from
tube end 18.
Tube 12 is released from
fixture 60, and the process for forming tube
end connector assembly 18 is essentially complete. The process may then be repeated on an opposite end of
tube 12, to provide a connector assembly using a similar, complimentary or even different
tube end connector 14. Under some circumstances, in some facilities, it may be possible to perform the process substantially simultaneously on both ends of a
tube 12, thereby completing the formation of tube
end connector assemblies 10 on both ends of
tube 12 at the same time.
The present invention provides a simplified process in which a connector can be attached at an end portion of a tube and can be restrained against axial movement on the tube in either direction. Radially outward upsets of the tube can be formed by impacting the tube axially at the tube end, while restraining the tube in a fixture and providing external support of the tube in regions where radially outward upsets are not desired and providing no external support of the tube where radially outward upsets are desired. A manufacturing process and a structure are provided whereby an o-ring or other sealing member is retained at the end of a tube.
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.